HATHKOPA, Bangladesh (AP)  After a tough game of soccer,
panting children cluster around a well and pump up gushes of
cool water, gulping it down greedily.

The well pipe is painted red, a warning that its water is
tainted with arsenic. The children, ages 5 to 13, drink anyway.

"My parents have warned me not to drink from this tube
well. But I'm too thirsty," says sixth-grader Nazmul Khan.

Eight years ago, as part of a two-decade-old project financed
by the World Bank and UNICEF, government engineers sank more
than 100 wells in Hathkopa, a village of 2,000 people 30 miles
east of the capital, Dhaka.

For the first time, the people of Hathkopa, who had repeatedly
been sickened by drinking from bacteria-infested ponds, got pure,
tasty water.

Then last year, public health surveyors made a stunning revelation:
Most of the millions of wells across Bangladesh are contaminated
by naturally occurring arsenic that is leaching into underground
aquifers. All but 10 of Hathkopa's hand-operated wells pump up
tainted water.

Low concentrations of arsenic like that in the water slowly
build up in the body, causing deadly cancers and other illnesses
that may not arise for years.

Authorities have no idea of the extent of the health disaster
because of the varying degrees of arsenic contamination, but
many of Bangladesh's 130 million people relied on well water.

A six-month study last year by Dhaka Community Hospital, which
specializes in studying arsenic poisoning, estimated that up
to 76 million people could be at risk.

Adults have stopped drinking from the dangerous wells, although
they still use the water for washing dishes and clothes. Many
people have gone back to collecting water from the village pond,
which they now boil or sterilize with purifying tablets. But
parents find it hard to keep the children away from the poisoned
wells.

"I don't drink water from this well, but my children
sometimes do," said Mumtaz Begum, a mother of three sons
and two daughters.

Bangladeshis are used to disasters that come with a fury:
cyclones roaring in from the turbulent Bay of Bengal, or floods
swamping as much as two-thirds of this country that is mostly
a vast, low-lying river delta. Each year, nature's rage kills
thousands.

But this latest affliction crept up slowly, quietly. What
people had welcomed for two decades as a bounty has become a
deadly curse.

"Thousands of Bangladeshi villagers have been unwitting
victims of what may be the biggest mass poisoning in history,"
the Bangladesh office of World Bank said in a report.

Conservative estimates suggest at least 100 people have died
of arsenic-related diseases in the past year and 1,000 have become
ill.

"This is just a tip of a huge iceberg. Most deaths from
arsenic-related poisoning is not known because the problem was
not detected until 1993," said Dr. Shibtosh Roy, a physician
at Dhaka Community Hospital.

The initial symptom is a thickening of the skin, like corns
and calluses on the hands and feet. In more advanced stages,
black patches appear on the skin, a form of cancer known as blackfoot
disease.

Early diagnosis is difficult because the warts look like calluses
from farming. It can take 10 to 20 years of prolonged consumption
before a person dies, and the process is reversible only if the
consumption is halted early.

Until the arsenic was first discovered in some wells five
years ago, the project that gave Bangladesh 4 million simple
wells was hailed as a major public health success story. It saved
tens of thousands of people who would have died form waterborne
diseases caused by drinking pond water.

In its study last year, the Dhaka Community Hospital examined
thousands of wells in 52 of the country's 64 districts. Most
of them were found to contain higher than the permissible level
of arsenic.

Under European and U.S. environmental laws, the maximum for
arsenic in drinking water is .05 gram per liter, although the
World Health Organization recently revised that to .1 gram per
liter. In some areas of Bangladesh, well water contains as much
as 100 to 900 times higher levels than that.

The World Bank and others are now searching for easy and affordable
alternatives to well water. Boiling pond water is one, but most
people are too poor to pay for the fuel. Building systems to
collect rain water is another possibility.